also use QPixmap for decorations (followup to r10926)

git-svn-id: http://svn.osgeo.org/qgis/trunk/qgis@10965 c8812cc2-4d05-0410-92ff-de0c093fc19c

src/gui/qgsmapcanvasmap.cpp

@@ -105,14 +105,7 @@ void QgsMapCanvasMap::render()
 
 QPaintDevice& QgsMapCanvasMap::paintDevice()
 {
-  if ( mUseQImageToRender )
-  {
-    return mImage;
-  }
-  else
-  {
-    return mPixmap;
-  }
+  return mPixmap;
 }
 
 void QgsMapCanvasMap::updateContents()